Season the meat an hour before preparing the grill. place brisket on a rimmed baking sheet.
Mix salt and pepper in a small bowl and season the meat all over (it should look like sand stuck to wet skin but without being caked on).
Let meat sit at room temperature for about an hour.
Prepare the grill for smoking. Fill chimney starter with charcoal, then light and let burn until coals are covered with a thin layer of ash.
Pour contents of chimney into one part of the grill. Then place a few chuncks o fwood next to (not on top of) the coals. (You want the wood to smolder, not catch fire and burn quickly). Place grate on grill, and position the the vent on lid on the far side of the grill from the hot coals to draw the smoke across the meat. Heat, adjusting vents to maintain a temperature of 225-250* (use a thermometer inserted through the top vent).
You'll know it is done when after rotating every 3 hours and flipping as needed, the meat is tender by not falling apart, and an instant read thermometer reads 195-205* when inserted into the thickest part of the meat. Typically 10-12 hours total.
After cooking, let the brisket rest at least 30 minutes, then slice against the grain into 1/4 inch slices.